Existed: Before 1939 – present Counties: Jeff Davis County Jeff Davis County, Texas | North end: SH 118 Length 2.49 km | |
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South end: Mt. Locke summit, McDonald Observatory | ||
Texas State Highway Spur 78 or Spur 78 is a spur road maintained by the Texas Department of Transportation (TxDOT) connecting the University of Texas at Austin's McDonald Observatory complex atop Mt. Locke to State Highway 118 15.2 miles (24.5 km) from Fort Davis. The road is 1.5 miles (2.4 km) long and is located within Jeff Davis County.
Contents
History
Spur 78 was not included on the 1933 official state highway map, but was in existence by 1939 when both the observatory was dedicated and the state's Highway Designation Files were created. Before 1941, the road connected the observatory to SH 166 until the section of that route between Fort Davis and the current intersection of SH 118 and SH 166 was re-designated as part of SH 118. In 1991 the only other intersecting highway, Spur 77, was created.
Route description
At its terminus at the summit of Mt. Locke, Spur 78 has the distinction of having the highest elevation at any point on the state highway system with an elevation of 6,791 feet (2,070 m). The route begins in front of the Otto Struve Telescope and Harlan J. Smith Telescope where there is a scenic overlook of the valley below and the surrounding Davis Mountains.
Initially the route has steep grades as it descends from the summit of the mountain. After 0.5 miles (0.8 km) the route intersects Spur 77 toward nearby Mt. Fowlkes where the observatory has another cluster of facilities. Spur 78 also intersects a few observatory service roads to maintenance facilities and residential areas. The observatory passes by the observatory's Frank N. Bash Visitors Center before terminating at SH 118.
Major intersections
The entire route is in McDonald Observatory, Jeff Davis County.